410 Chain Riveting\ may not be too large. The efficiency will be reckoned on the pitch line as before, because the joint is weakest along that line, X" ; F HJ£ T the links being most crowded there. The fracture should always be allowed to take place preferably on the pitch line. All the. seams given may have two butt straps instead of a lap, and the dangerous bending action be thereby removed, see Pig. 362.